Calvin Coolidge takes the oath of office on March 4, 1925. Coolidge, like Trump, took an "America First” approach to international affairs.AP

The last few days—as President Donald Trump has savaged America’s allies over trade, demanded that they readmit Russia to the G7, and embraced North Korean dictator Kim Jong Un—make something clear: Cold War conservatism is dead. What’s replacing it resembles less the foreign-policy outlook that has animated conservatives since World War II than the sentiment that prevailed before it.

In the 1920s, conservative Presidents Warren Harding, Calvin Coolidge, and Herbert Hoover rejected both binding alliances and the notion that America should make economic sacrifices to uphold the geopolitical order. They saw little difference between Britain and France, which were more democratic, and Germany, which was more authoritarian, and insisted that America remain independent from them all. They opposed Woodrow Wilson’s dream of requiring America to aid European nations threatened with aggression through the League of Nations. And, among some conservatives, this fear of binding international commitments continued well into the 1940s. As late as 1949, Ohio Senator Robert Taft—dubbed “Mr. Republican”—voted against the North Atlantic Treaty Organization because NATO, like the League, restrained America’s freedom of action. “It obligates us,” Taft warned, “to go to war if at any time during the next 20 years anyone makes an armed attack on any of the 12 nations.”

But over time, the impact of World War II, and fear of the Soviet Union, largely overcame these anxieties, and Cold War conservatism was born. To justify America’s struggle against virulently anti-democratic powers, conservatives began defining America’s global role ideologically. The United States would lead the free world against its despotic foes.

The narrative created by World War II—of America heroically joining its allies to save the world from Nazi tyranny—countered conservative fears about binding commitments. And, Taft notwithstanding, a 1948 poll found that two-thirds of Democrats and Republicans alike supported the creation of NATO. “Politically speaking, isolationism has disappeared as far as mutual treaties against aggression are concerned,” explained the pollster George Gallup. Not only did most conservatives support NATO, by the 1950s most supported the Eisenhower administration’s effort to replicate it in regional pacts like SEATO (the Southeast Asian Treaty Organization) and CENTO (the Central Treaty Organization). Cold War conservatives still took a dim view of the United Nations, which, in their minds, sapped America’s sovereignty while amplifying the voices of its foes. But they became staunch defenders of America’s military alliances. Sovereignty was important, but defending the nations menaced by Soviet communism came first.

The need to sustain alliances also reshaped views of foreign aid. Taft not only opposed NATO—along with business groups like the Chamber of Commerce and the National Association of Manufacturers, he also opposed the Marshall Plan on the grounds that, in order to pay for it, the government might raise taxes. But by the 1950s, conservatives were willing to ship money overseas if it strengthened America’s anti-communist allies. In his book The Conscience of a Conservative, Barry Goldwater, while decrying the fact that, “increasingly, our foreign aid goes not to our friends, but to professed neutrals” defended delivering “military and technical assistance to those nations … that are committed to a common goal of defeating world communism.”

Anti-communism also contributed to conservatives’ embrace of free trade. Since the 19th century, the Republican Party had championed protectionism. Republicans had overwhelmingly supported the Smoot-Hawley bill that in 1930 raised tariffs on 20,000 types of imported goods. As late as 1946, notes the Dartmouth economist Douglas Irwin, author of Clashing over Commerce: A History of U.S. Trade Policy, congressional Republicans almost torpedoed the negotiations that led to the tariff-reducing General Agreement on Tariffs and Trade.

In the 1950s and 1960s, however, the GOP moved decisively in favor of free trade. Partly that’s because American businesses—which were becoming increasingly multinational—wanted lower trade barriers so they could take advantage of markets abroad. The United States had also finished World War II in such a commanding economic position that few Americans worried foreign competition would threaten their jobs. But the shift was also the result of the Cold War. Conservatives as well as liberals argued that by exporting goods to the U.S., America’s European and Asian allies could build the economic strength necessary to contain the U.S.S.R. The struggle against communism also made protectionism ideologically uncomfortable. If leading the free world meant championing the free market against Soviet-style government planning, then it was hard to justify government barriers to free trade.

If the Cold War made conservatives more solicitous of America’s democratic friends, it also inclined them toward a harder line against America’s anti-democratic foes. Often, the ideological distinction between democracy and despotism was clearer in theory than on the ground. American conservatives depicted democratically elected leftists like Chile’s Salvador Allende as Stalinists and defended South Africa’s apartheid regime as preferable to Nelson Mandela’s Soviet-backed African National Congress. But World War II had not only made alliances a source of pride, it made “appeasement”—a term that previously lacked negative connotations—a source of shame. Standing with your democratic allies evoked Normandy. Bowing to your dictatorial foes evoked Munich.

Cold War presidents—including Republicans like Richard Nixon and Ronald Reagan—negotiated with the U.S.S.R. But when they did, conservative intellectuals and activists often compared them to Neville Chamberlain. In a 1977 essay decrying the Nixon, Ford, and Carter administration’s pursuit of détente with the U.S.S.R., the Commentary editor Norman Podhoretz warned that “the response of the United States to the Soviet military buildup … has uncannily followed the pattern of British response to the German buildup of the Thirties.” When Ronald Reagan signed the Intermediate-Range Nuclear Forces deal with Mikhail Gorbachev, conservatives ran ads declaring, “Appeasement is as unwise in 1988 as in 1938.”

When the Cold War ended, something remarkable happened: Conservative rebels began advocating a return to the international outlook that preceded World War II. Running for president in 1992 and 1996, Pat Buchanan argued that not merely the UN, but NATO too, threatened American sovereignty. America should become again, he argued, a “republic that always retains the constitutional freedom to decide when, where and whether to fight.” Resuscitating the pre-World War II slogan, “America First,” he railed against NAFTA and the World Trade Organization.

For Buchanan, the ideological divisions of the Cold War were obsolete. By stealing American jobs, capitalist democracies like Germany and Japan threatened Americans more than Russia. The key global divides, he argued, were now not ideological but national and civilizational. America must defend its sovereignty and economic well-being against global institutions and foreign competitors regardless of their democratic credentials. And “the West”—defined less by its form of government than by its religious and racial heritage—must defend itself against penetration by non-Christians and nonwhites. “If we had to take a million immigrants in, say Zulus, next year, or Englishmen,” Buchanan mused in 1991, “what group would be easier to assimilate and would cause less problems for the people of Virginia?” Invoking the lessons of Munich, Cold War conservatives like John McCain and Bill Kristol in the 1990s supported the Clinton administration’s efforts to repel Serbia’s invasions of Croatia, Bosnia, and Kosovo. But the “invasions” that most bothered Buchanan were those across America’s southern border led by people he called “Jose.”

September 11 temporarily buried the Buchananite challenge. George W. Bush made Cold War conservatism his template for the War on Terror. He depicted America’s post-9/11 struggle not as civilizational but ideological. America’s new foe was not Islam—a “great religion” that al-Qaeda had “hijacked”—but a new form of tyranny. “They are the heirs of all the murderous ideologies of the 20th century,” Bush told Congress nine days after the attacks. “They follow in the path of fascism, and Nazism, and totalitarianism.”

Bush quarreled with American allies like France and Germany that refused to support his invasion of Iraq. But he insisted that democracies were America’s natural allies and dictatorships its natural foes. “It is the policy of the United States,” Bush declared in his second inaugural address, “to seek and support the growth of democratic movements and institutions in every nation and culture.” And he treated economic competition with America’s democratic allies as an afterthought. “Powerful secular trends are moving the world toward economic openness,” wrote Bush’s future national-security adviser and secretary of state, Condoleezza Rice, in a 2000 essay laying out his foreign-policy vision. For Rice and Bush, the benefits of such trends were self-evident.

Over the last week, Donald Trump has shown—more clearly than ever before—that he is Buchanan’s heir, not Bush’s. He has challenged the Cold War conservative template in three fundamental ways. First, by imposing tariffs on America’s closest democratic allies and blowing up the G7 meeting when they objected. Second, by demanding that the G7—which includes only democracies—reinstate authoritarian Russia. And, third, by lavishly praising the North Korean dictator Kim Jong Un.

Conservatives who still hew to the Cold War template have indignantly juxtaposed these acts with America’s past unity with its democratic allies, and its past fortitude against dictatorial foes. The former Bush adviser Matthew Dowd contrasted Trump’s behavior at the G7 with Dwight Eisenhower, who urged “comradeship, patience, and compromise among all free nations.” The Weekly Standard editor Jonathan Last contrasted Reagan’s denunciations of the Soviet Union (“Mr. Gorbachev, tear down this wall”) with Trump’s flattery of Kim Jong Un (“His country does love him”).

But in deviating from Cold War conservatism, Trump—like Buchanan—is in key ways resuscitating the conservative foreign-policy outlook that preceded it. If the belief in small government and in traditional morality are American conservatism’s essence, then the Republican presidents of the 1920s—Warren Harding, Calvin Coolidge, and Herbert Hoover—were certainly conservative. But they treated neither allies nor adversaries the way today’s Cold War conservatives demand. They treated them more like Trump does.

In popular discourse, American foreign policy in the 1920s is often described as isolationist. But the historian Joan Hoff Wilson’s phrase, independent internationalism, better captures the reality. The United States was not absent from world affairs in the 1920s. What the presidents of the era rejected was the very thing Trump is rejecting today. They refused to divide the world into allies and adversaries, and they refused to compromise American sovereignty, or America’s perceived economic interests, to strengthen the former against the latter.

If World War II gave alliances a good name, World War I had given them a bad one. When Americans in the 1920s looked back on their fight alongside Britain and France in 1917 and 1918, they didn’t summon the kind of heroic images conjured by Normandy. To the contrary, they looked back on what the historian William Leuchtenberg has called “a dirty, unheroic war which few remembered with any emotion save distaste.” Among the alleged culprits were America’s former wartime allies. In the 1920s, influential “revisionist” historians like Harry Elmer Barnes argued that America’s allies, Britain and France, bore more responsibility for the war than its adversary, Germany.

Taking office in this environment in 1921, Warren Harding promised “sustainment in triumphant nationality” not “submergence in internationality.” His secretary of state, Charles Evans Hughes, insisted that, “cooperation … does not mean and never has meant alliances or political entanglements.” This not only meant staying out of the League of Nations, an organization whose mail the Harding administration at first would not even answer. It also meant spurning British and French efforts to revive the wartime alliance so as to contain Germany. If the phrase “No friends, no enemies” encapsulates the Trump Doctrine, as a senior administration official recently told my colleague Jeffrey Goldberg, it encapsulated Harding’s too.

Again and again in the 1920s, American presidents refused to show Paris and London any special favor. In 1923, when Germany defaulted on its wartime reparations, France and Belgium sent troops into the Ruhr Valley to seize German mines and steel plants as collateral. But instead of supporting France’s action, Harding withdrew the remaining U.S. troops from the Rhineland, signaling that the United States would not aid France if Germany further violated the Treaty of Versailles. Four years later, in a backhanded bid at an alliance, France proposed an agreement with the United States forswearing war between the two nations. But Calvin Coolidge’s secretary of state, Frank Kellogg, foiled the effort by inviting other countries to renounce war as well. The result was the Kellogg-Briand Pact, in which 62 nations promised not to take up arms, and which left America no more obligated to France than it had been before.

Although they disliked the communist U.S.S.R., the conservative presidents of the 1920s did not stress ideological distinctions between friends and foes in the way conservatives did during the Cold War. In Coolidge’s words, “We are independent, detached, and can and do take a disinterested position in relation to international affairs.”

And, like Trump today, the presidents of the 1920s embraced protectionism with little regard for its geopolitical consequences. In 1922, Harding signed the Fordney-McCumber bill, which created the highest tariffs in American history. Then, in 1930, Hoover signed Smoot-Hawley. The United States also refused to forgive its former allies’ war debts. Coolidge’s notorious line—“They hired the money, didn’t they?”—may be apocryphal, but it captured the spirit of his policy.

When Trump, in an interview after the G7, complained that “we have been taken advantage of as a country for decades by friends and enemies both,” and when National-Security Adviser John Bolton tweeted the now-famous photo of German Chancellor Angela Merkel glaring at Trump alongside the caption, “Just another #G7 where other countries expect America will always be their bank,” they were echoing Coolidge.

There are obviously important differences between Trump’s foreign policy and American foreign policy almost a century ago. In the 1920s, for instance, when America’s standing army was small, presidents prided themselves on their anti-militarism. Today, America possesses the world’s largest military, by far, and Trump is not only vowing to expand it, but almost casually threatens war.

But what links Trump and the conservative presidents of the 1920s is their view of all foreign governments, regardless of ideology, as alien and predatory, and their desire not to bind America to any of them. It’s no coincidence that, in both eras, this obsession with American sovereignty has followed disillusioning wars, nor that, in both eras, it has coincided with a panic about immigration. Both Trump’s slogan, “Make America Great Again,” and Harding’s, “Back to Normalcy,” evoke nostalgia for a time when America, and native-born Americans, were more clearly masters of their own fate.

In both eras, as well, the insistence that foreign governments have cheated America is bound up with the insistence that foreign people have cheated Americans. As vice president, Coolidge warned that “the unassimilated alien child menaces our children,” and that “biological laws tell us that certain divergent people will not mix or blend.” The Second Klan reached its peak in the 1920s, riding a surge of xenophobia to enroll millions of members. And in 1924, Congress passed sweeping immigration restrictions. Hostility to immigration was widespread among rank-and-file conservatives of the era, as it is today.

Many contemporary conservative elites, who are deeply invested in the template created by the Cold War, find Trump’s behavior at the G7 and in Singapore appalling. But both opinion polls and local election results suggest that their arguments hold little currency among grassroots conservatives. There is no large-scale, anti-Trump wing of the Republican Party. And it’s not hard to understand why. George W. Bush’s neo-Cold War foreign policy proved disastrous. And given the right’s long-standing devotion to American sovereignty, America First is the historic alternative, especially when—as in the 1920s—there are few obvious or imminent threats.

At a time of relative peace and prosperity, America’s government is shedding collective responsibilities overseas while acting brutally to restore racial and religious hierarchies at home. Some Cold War conservatives may believe this violates American tradition. But, like it or not, Trump is an heir to American tradition too.

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Peter Beinart is a contributing editor at The Atlantic and a professor of journalism and political science at the City University of New York.